Designer-Gateway Comm via RPC


I’ve created a simple example, almost identical to the Design Best Practice in Section 4.6 of the programming guide (p.47). I’ve added a toolbar button that invokes a method, but an error is thrown:

com.inductiveautomation.ignition.client.gateway_interface.GatewayException: Gateway Error 500: Unable to read response from Gateway. at com.inductiveautomation.ignition.client.gateway_interface.GatewayInterface.newGatewayException( at com.inductiveautomation.ignition.client.gateway_interface.GatewayInterface.getResponse( at com.inductiveautomation.ignition.client.gateway_interface.GatewayInterface.sendMessage( at com.inductiveautomation.ignition.client.gateway_interface.GatewayInterface.sendMessage( at com.inductiveautomation.ignition.client.gateway_interface.GatewayInterface.moduleInvoke( at org.test.pkg.designer.TestModuleRPCProxy.invoke( .. . Caused by: org.xml.sax.SAXParseException: The end-tag for element type "Response" must end with a '>' delimiter. at Source) .. .
The getRPCHandler method is called in the GatewayHook, but I haven’t been able to determine what is happening beyond that.

Is this something that has been encountered before? Any advice on where I might be going wrong?


Update on this one:
The error was a bit cryptic. The problem was in my build file. I mistakenly packed the jar file of the common project before adding it to the module, so a NoClassDefFoundError occurred when I invoked the RPC method, and didn’t show up in the logs.
Problem solved.